[firebase-release] Updated SDK for Cloud Functions to 0.5.2

[firebase-release] Updated SDK for Cloud Functions to 0.5.1

Propagate rejected promise from user function (firebase#104)

Fix path for new event payload. (firebase#50)

v0.3.1 + small README update (firebase#46)

set version to 0.3.0 \o/ (firebase#41)

Release 0.2.2 (firebase#21)

* update package version to 0.2.2
* update the peer dependency on Firebase to ^3.1.0 (back on public releases)
* rebuild library
  * blew away `lib` and `typings` folders
  * was getting errors regenerating
  * updated to the latest version of `typescript`, `tsc`, and `typings`
  * generated `lib` contained `src` and `test` dirs. Updated `tsconfig.json` to fix this and remove test files
  * regenerate successfully

Only create event.app on first use (firebase#16)